Abstract:

【Objective】 The tissue- and developmental-specific expression of cathepsin B (CTSB) and cystatin B (CSTB) mRNA transcripts in porcine were studied in order to understand the genetic mechanism of tenderness traits. 【Method】 The expression of CTSB and CSTB mRNA in different tissues and different development phases were revealed by Taqman real-time PCR analyses. 【Result】 In adult pigs, CTSB mRNA and CSTB mRNA expression were widely detected in many tissues. The highest level of expression occurred in kidney and the lowest were in myocardium and skeletal muscle, respectively. The quadriceps femoris muscle had significantly higher CSTB mRNA expression than m. longissimus dorsi muscle (P＜0.01). The expression of CTSB mRNA in m. longissimus dorsi muscle increased first then decreased in 0-5-month-old of age of Landrace and Meishan pigs. The peak of expression occured earlier in Meishan than in Landrace. Continuously decreased expression patterns of CSTB mRNA were detected among different months in m. longissimus dorsi muscle of Meishan pig. And in Landrace pig the expression peaked at 2 months of age, then decreased. 【Conclusion】 These results indicate that the expression of CTSB and CSTB mRNA are influenced by tissue, developmental phases and breed factors. There is a significant positive correlation between CTSB and CSTB mRNA expression.

Key words: pigs, Cathepsin B gene, Cystatin B gene, expression, tenderness